The present invention relates to a perpendicular recording magnetic head, a manufacturing method thereof, and a magnetic disk storage apparatus which incorporates the same.
A magnetic disk storage apparatus incorporates a magnetic recording medium and a magnetic head, and data on the recording medium is read or written by the magnetic head. In order to increase the capacity of the magnetic disk storage, the areal density has to be increased. However, in the conventional longitudinal recording method, the thermal fluctuation in medium magnetization prevents one from achieving the higher areal density. A solution to this problem is a perpendicular recording method whereby the recorded magnetizations are aligned in the direction perpendicular to the medium.
The perpendicular recording method is available in two types: one type uses a double-layered perpendicular medium having a soft underlayer and the other type uses a single-layered perpendicular medium having no soft underlayer. When a double-layered perpendicular medium is used as a recording medium, it is necessary to use a single-pole type head which has a main pole and an auxiliary pole for recording. In this case, a higher magnetic field intensity can be applied to the medium. Taking into consideration that the head may have a skew angle, it is desirable that the shape of the main pole is trapezoidal that the width of the leading side is smaller than that of the trailing side. FIG. 2 schematically shows the structure of a conventional magnetic head including a single-pole type head. As shown in FIG. 2, a conventional magnetic head includes a lower shield 8, a read element 7, an upper shield 9, an auxiliary pole 3, a thin film conductor coil 2, and a main pole 1 which are laminated in the downtrack direction (from the leading side) in the order of mention. The lower shield 8, read element 7 and upper shield 9 constitute a read head 24 while the auxiliary pole 3, thin film conductor coil 2 and main pole 1 constitute a write head (single-pole type head) 25. Japanese Patent Laid Open Publication No. 2003-45008 describes a single-pole type head in which a shield for an external magnetic field is located with a gap film between the main pole and shield in a way to be recessed from the surface opposite to the medium.